Chromic sulfide

A How many grams of chromic sulfide will be formed from 0.718 grams of chromic oxide according to the equation... 

Usually, organoboranes are sensitive to oxygen. Simple trialkylboranes are spontaneously flammable in contact with air. Nevertheless, under carefully controlled conditions the reaction of organoboranes with oxygen can be used for the preparation of alcohols or alkyl hydroperoxides (228,229). Aldehydes are produced by oxidation of primary alkylboranes with pyridinium chi orochrom ate (188). Chromic acid at pH < 3 transforms secondary alkyl and cycloalkylboranes into ketones pyridinium chi orochrom ate can also be used (230,231). A convenient procedure for the direct conversion of terminal alkenes into carboxyUc acids employs hydroboration with dibromoborane—dimethyl sulfide and oxidation of the intermediate alkyldibromoborane with chromium trioxide in 90% aqueous acetic acid (232,233). 

Dinitrotoluene is oxidized to 2,4-dinitrobenzoic acid [610-30-0] by potassium permanganate or chromic acid, and is reduced to 2,4-diaminotoluene by iron and acetic acid. It is reduced partially by zinc chloride and hydrochloric acid to 2-amino-4-nitrotoluene [99-55-8] and by ammonium sulfide to 4-amino-2-nitrotoluene [119-32-4],... 

The technology is primarily applicable to the removal of inorganic fumes, vapors, and gases (e.g., chromic acid, hydrogen sulfide, ammonia, chlorides, fluorides, and SOj) volatile organic compounds (VOC) and particulate matter (PM), including PM less than or equal to 10 micrometers ( m) in aerodynamic diameter (PM,q), PM less than or equal to 2.5 m in aerodynamic diameter (PMj 5), and hazardous air pollutants (HAP) in particulate form (PM ap)-... 

Acetic acid, acetone, alcohol, aniline, chromic acid, hydrocynanic acid, hydrogen sulfide, flammable liquids, flammable gases, and mtratable substances, paper, cardboard and rags. 

The oxidation of sulfides to the corresponding sulfoxides and sulfones proceeds under rather strenuous conditions requiring strong oxidants such as nitric acid, hydrogen peroxide, chromic acid, peracids, and periodate. Using MW irradiation, this oxidation is achievable under solvent-free conditions and with desired selectivity to either sulfoxides or sulfones using 10% sodium periodate on silica (Scheme 6.34)... 

Chromic(VI) acid Acetic acid, acetic anhydride, acetone, alcohols, alkali metals, ammonia, dimethylformamide, camphor, glycerol, hydrogen sulfide, phosphorus, pyridine, selenium, sulfur, turpentine, flammable liquids in general... 

The higher sulfides of tellurium such as TeS2 and TeSs, are obtained from tellurite solutions by precipitation with hydrogen sulfide or sodium sulfide. Tellurium reacts with concentrated sulfuric acid to form red oxysulfide of the composition, TeSOs. With nitric acid, the metal is oxidized to dioxide, Te02. Oxidation of tellurium with chromic acid or potassium permanganate in nitric acid yields orthotelluric acid (HeTeOe). 

Scheme 34 shows the synthesis of the bc portion (336), which possessed three of the nine asymmetric centers present in cobyric acid. Retrosynthesis determined that (336) could be obtained, via sulfide contraction, from the two intermediates (337) and (338). Ring c was synthesized from (+)-camphor quinone (not shown). Ring b (337) was obtained from 8-methyl-j8-acetylacrylic acid (339), the two adjacent chiral centers being generated in the required relative orientation by a Diels-Alder cycloaddition with butadiene in the presence of tin(IV) chloride. Fractional crystallization served to resolve the diastereomeric a-phenethylamine salts derived from them, eventually affording the compound (340). Oxidation with chromic acid cleaved the double bond in (340) and one of the newly generated... 

Chromates, Dichromates, Trichromates T etra-chromates. See p C274-Lff Chromic Acid. See p C298-R to C299-L Chromium and Its Compounds. See pp C300-Lff Diazonium compounds and sodium sulfides react vigorously and are known to explode. Similar explosive reactions have been observed with H2S, also (Refs 40 41)... 

Inorganic pigments are found in the earth. Iron and lead oxides provide earth colors. Copper calcium silicate and cobalt stannate provide blues. The colors burnt sienna and burnt umber come from iron oxides. Green pigments come from chromic oxide, calcinated cobalt, and zinc and aluminum oxides. Red pigments come from cadmium sulfide, cadmium selenide, and barium sulfate. All these chemical compounds come from the earth. 

The oxidation of sulfides to sulfoxides is a facile transformation for which many reagents have been employed in the literature. These include hydrogen peroxide, ozone, nitric acid, chromic acid or tert-butylhypochlorite. Here, meto-chloroperbenzoic acid is used to oxidize a-phenylthio ketone 14, and successive elimination of the resulting a-phenylsulfinyl ketone 15 by heating at reflux in benzene provides the or,ji3-unsaturated ketone 16. Because of their thermal instability sulfoxides easily undergo elimination. The mechanism is explained by Cram as stereospecific cw-elimination. ... 

OXIDATION, REAGENTS Dimethylsulf-oxide-Acetic anhydride. 1-Amyl hydroperoxide. N-Bromosuccinimide. Ceric ammonium nitrate. Chloramine. o-Chlo-ranil. 1-Chlorobenzotriazole. N-Chloro-succinimide-Dimethyl Sulfide. Chromic acid. Chromic anhydride. Chromyl chloride. Cobalt(ll) acetate. Cupric acetate monohydrate. Cupric nitrate-Pyridhic complex. 2,3-Dichloro-5,6-dicyano-l, 4-benzoquinonc. Dicyclohcxyl-18-crown-... 

Oxidation of sulfides to sulfoxides, however, is more efficiently accomplished by reaction with sodium metaperiodate, or hydrogen peroxide, ozone, peracids, manganese dioxide, nitric acid, chromic acid, and other oxidants. See. for example, N. J.. Leonard and C. R. Johnson, J. Org. Chem., 27, 283 (1962). 

The main applications of oxidation with chromium trioxide are transformations of primary alcohols into aldehydes [184, 537, 538, 543, 570, 571, 572, 573] or, rarely, into carboxylic acids [184, 574], and of secondary alcohols into ketones [406, 536, 542, 543, 575, 576, 577, 578, 579, 580, 581, 582, 583, 584]. Jones reagent is especially successful for such oxidations. It is prepared by diluting with water a solution of 267 g of chromium trioxide in a mixture of 230 mL of concentrated sulfuric acid and 400 mL of water to 1 L to form an 8 N CrOj solution [565, 572, 579, 581, 585, 556]. Other oxidations with chromic oxide include the cleavage of carbon-carbon bonds to give carbonyl compounds or carboxylic acids [482, 566, 567, 569, 580, 587, 555], the conversion of sulfides into sulfoxides [541] and sulfones [559], and the transformation of alkyl silyl ethers into ketones or carboxylic acids [590]. 

Dibutyl sulfide is converted into dibutyl sulfoxide with one equivalent of peroxytrifluoroacetic add and into dibutyl sulfone with two equivalents of peroxytrifluoroacetic acid [279]. On the other hand, with manganese dioxide, dibutyl sulfide yields dibutyl sulfoxide exclusively 541], and with chromic acid, it yields dibutyl sulfoxide, even when an excess of the oxidant is used and even when the reaction is carried out at 100 °C 541] (equation 552). 

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